Efficient Sample Location Selection for Query Zone in Geo-Social Networks

Algorithm 1

Sample location selection.

Input: a set of anchor points and a positive integer ;

Output: the sample locations and ;

1: choose center points out of ;

2: assign each other anchor point to the subset of its nearest center by using Voronoi diagram;

3: repeat

4: a point from , where is the extremal set of ;

5: randomly choose a subset other than the extremal subset ;

6: if then

7: , ;

8: end if

9: until the value of does not change anymore

10: return the optimal point of each subset and ;